Influential psychiatrist Dr. Robert Spitzer, who campaigned to remove homosexuality from the Diagnostic and Statistical Manual of Mental Disorders in the 1970s, has died. He was 83.

The Columbia University psychiatrist died on Christmas Day in Seattle of complications from heart disease, said his wife, Janet Williams, the Washington Post reports.  He also had Parkinson’s disease.

Dr. Spitzer brokered the American Psychiatric Association’s 1973 vote to stop treating homosexuality as an illness. Then, taking the helm at the APA’s Diagnostic and Statistical Manual of Mental Disorders (DSM) — the profession’s bible — he led a push for uniform standards in an often ambiguous discipline.

He added dozens of mental disorders to the psychiatric lexicon: anorexia, bipolar disorder, panic disorder, PTSD and many other now-familiar maladies.

Although such ailments existed before the 1970s, they had no agreed-upon names or definitions until Dr. Spitzer branded them in two new editions of the DSM and helped press for improvements in treatment.